Cutting tip or the like



April 12,1927.

G. L. WALKER CUTTING TIP OR THE LIKE Filed on, 12, 1925 I/VVENTOI?ATTORNEY Patented Apr; 112, 192?.

UNHTEE STATEfi GEORGE Il- WALKER, OF NEW YORK, N. Y., ASSIGNOR TO AIRREDUCTION COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OENEW YORK.

CUTTING TIP OR THE LIKE.

Application filed October 12, 1925. Serial No. 62,183.

This invention relates to torches for cutting metal by means of anoxygen jet assisted by one or more heating, or preheating, jets composedof a mixture of oxygen and a combustible gas. These torches arecustomarily provided with removable and interchangeable members or tips,which are inserted in or applied to the heads of the torches to receiveand conduct the gases for the several jets and to combine the gases forthe preheating jets. The purpose of this invention is to provide acutting tip, plug, or the like, having important advantages over priorcutting members; one of these advantages being the lowness of thepressures that can be employed, and another being the improved mixing ofthe gases for the preheating flames, and the increased stability ofthese flames, whether the combustible gas is one under very low pressureor one under substantial pressure.

The cutting tips heretofore commonly employed have been suitableforacetylene or other gases available under some pounds of pressure, butare not suitable for use with ordinary illuminating gas, which is atavery low pressure. For a great deal of cutting, a

combustible gas of high calorific value, such as acetylene for instance,is not really required; and it would be a saving, as well as a greatconvenience, if illuminating gas,

which is piped everywhere, could be used satisfactorily with torches ofstandard design and dimensions.

The limits of space and possible arrangement in the rear ends of tips ofthese torches have made it impossible to drill passages in such numberand--elation as tointroduce an adequate amount of very low pressurecombustible gas to mixwith the high pressure oxygen for the preheatingjets. ficulty is met in the present invention by a construction thereinthe low pressure gas for the. preheating jets is admitted, not bylaterally drilled bores, but by means of a transverse slot or out, whichslot intervenes between each oxygen inlet jet bore and the rear orcombining end of each preheating mixture passage, in such manner thatthe oxygen jets striking across the slot entrain a full complement ofthe low-pressuregas.

The construction produces a very ad vantageous mixing of the gases, andthe preheating flames are of excellent character.

These advantages "are equally noticeable in The difcases where thecombustible gas is under a considerable degree of pressure. The tip hasbeen found, for example, to give especially good results with calorinegas under pressures of from a fewounces up to 5 pounds, or more;calorine being a combustible gas with which it is usually somewhatdiflicult to obtain stable and reliable preheating flames for cuttingpurposes. The object of the invention is to secure these advantages in aconstruction 'which is simple and inexpensive to make, and which isadapted for tips of all sizes and with any number of preheating jetseach provided with its own mixing arrangement.

1n the accompanying drawings, forming part hereof:

Fig. 1 is a side view of the forward part of a cutting torch, showingthe supply conduits in elevation, the head of the torch in centralvertical section, and the tip in elevation;

hFig. 2 is an enlarged axial section through t e tip;

Fig. 3 is a cross-section on the line 3-3 of Fig. 2'; and i Fig. 4- is asimilar view illustrating a modification.

The torch has conduit pipes 2, 3, 4, for cutting oxygen, preheatingoxygen, and .combustible gas, respectively. These pipes form part of, orextend through, the handle, arm or stock of the torch, and theconnections at the rear end may be of the customary character. It will,therefore, be understood,

that the illustration represents an apparatus so designed and connectedthat the v pipe 2 conducts oxygen under high pressure,

for cutting, the pipe 3 conducts oxygen under a lower, but stillsubstantially high, pressure, to serve the preheating jets, while thepipe 4 conducts very low pressure combustible gas, for the same jets.

The several pipes deliver into ducts 12, 1 3 and 14. drilled in the head5, and having their forward ends opening, at different points, into atruncated conical, or like, cavity 6 in Mead.

The -t p 7 has a truncated conical rear portion 8, which fits saidcavity, and is finished to make seals therewith between the respectivegases. Within this sealing portion, the tip is formed with ample annulargrooves, or circumferential recesses, 9, 10, whichregister,respectively, with the ducts 13 and 14 in the head. The duct 12of the head delivers into the rear or upper extension of the cavity 6,the cutting oxygen there entering the rear endof a longitudinal cuttingoxygen passage 15, extending through the tip and delivering at theforward end through the central cutting jet orifice 16.

In addition to the cutting oxygen passage 15, these tips are drilledwith a plurality of longitudinal combustible mixture passages 17, fordelivering a group of preheating flame jets, through orifices 18, aboutand adjacent the cutting oxygen jet. In some instances a singlepreheating jet, placed ecr'cntrically or laterally from the cutting jetpassage, may be employed.

The preheating mixture passages are supplied with oxygen for supportingcombus tion. through restricted bores 19 which are drilledlongitudinally to intersect the side chamber 9. These bores are quiterestricted, to deliver velocity jets of the high-pressure oxygen gas,and are in line with the rear ends of the preheating mixture passages17.

A comparatively narrow, annular slot or cut 20 is made in the rear partof the tip, transversely inward from the side chamber 10, to intersectthe alined axes of the bores 19 and 17. This slot extends inwardsomewhat beyond the passages 17, still leaving. however, sufficient wallabout the central passage 15, and affords an aspirating chamber, acrosswhich strikethe jets from the oxygen inlets 19, so as to entrain thelow, or relatively low, pressure combustible gas into the exits 21. Inthis way an ample proportion of low-pressure illuminating gas isinjected and driven along in mixture with oxygen to feed the preheatingjets of one of these cutting tips. Furthermore, superior gas mixing andflame are obtained, either with illuminating gas or with other kinds ofgases under higher pressures, as heretofore stated.

The forward or delivery ends of the oxygen jet bores 19 terminate at therear face of the narrow slot 20. The construction does not require theinsertion of projecting jet nozzles to secure the desired degree ofaspirating effect, the purpose of the invention being to obtain a veryefiicient action under the conditions indicated by a very simple andinexpensive construction, which is well adapted to the restricted spacein the rear end of the tip. It will be apparent that the constructioncan be readily embodied in small as, well as in large or medium sizedtips, and in tips of any size having numerous preheating jet passageseach provided with its individual entraimng oxygen jet. By properlyproportioning the passages 17 and 19, or 21 and 19, and the width of theslot, the exact relation for the desired degree of aspiration can befixed and can be reproduced substantially without variation in all tipsof a given size and character. The effect of the oxygen jet strikingacross the narrow slot occupied by the combustible gas has been found tobe'advantageous for moving the low pressure gas, for proportioning thegases and for initiating a thorough mixing. 7

The result is more effective, especially in large size tips, when therear ends, 21, of the preheating mixture passages are reduced withreference to the major portion of the length of these passages, so as toform short, comparatively narrow tubes, within which the combined gasesare first injected by the entraining action of the oxygen jets, thegases thence spreading out to fill the long, comparatively Wide boreswithin which the mixing is completed before the gases escape from theflame jet orifices 18.

The passages 17, 21 and 19 are formed by counter-boring from the frontend of the tip, the bores 17 being comparatively wide up to the shorttubes 21, which are materially narrower than the long bores 17, and thebores 19 being quite fine. Proportions may, of course, be varied, butsatisfactory results are secured, for example, when the oxygen jet bores19 are about one-sixth the diameter of the rear ends of the mixingpassages, and the width of the slot 20 is about one-half that diameter.The diameter of the bores 17 is determined by the desired size of thepreheating jets. In smaller tips the passages 17, 21 may be of onediameter.

Fig. 4 illustrates a modification wherein the slot orcut 20" forming theaspirating chamber, instead of being a continuous annular groove, is outin by a suitable cutter from the several sides so as to intersect thebores 19 and 21.

Various other forms will suggest themselves. I do not necessarily limitthe invention to embodiment in an integral tip including the deliveryorifices, as sometimes these structures are divided into a rear partwhich fits into the head, and a delivery part or nozzle which can betaken out and replaced with another, if desired, without replacing therear part at each exchange.

I claim:

1. A cutting torch tip or member having one or more preheating mixturepassages, with a restricted oxygen jet bore in line with each preheatingmixture passage, said memher being formed with a narrow transverse slotto afford inlet for combustible gas, the delivery ends of said oxygenjet bores terminating at the rear face of said slot, said slotintervening between the delivery ends of said oxygen jet bores and therear ends of said preheating mixture passages, in such manner that theoxygen jets striking across the slot entrain the combustible gas.

2. A cutting torch tip or member provided with a centralcuttingoxygenpassage and one or more eccentric preheating mixture passages,with a restricted oxygen jet bore in line with each preheating mixturepassage, said member being formed with a narrow transverse slot toafford inlet for comhustible gas, the delivery ends of said oxygen jetbores terminating at the rear face of said slot, said slot interveningbetween the delivery ends of said oxygen jet bores and 10 the rear endsof said preheating mixture assages in such manner that the oxygen Petsstriking across the slot entrain the comustible gas, each preheatingmixture passage comprising a relatively wide bore throughout the greaterpart of its length with a relatively reduced bore at the rear end formina short, comparatively narrow tube into w ich the gases are injected.

GEORGE L. WALKER.

